Pressure sores, and their resulting ulcers, can begin long before a patient is lying on a hospital bed. Pressure sores can result from a person being placed upon a hard hospital transportation cart, an operating room table, a CAT scanner, a cardiac or day chair, or even a wheelchair for an extended period of time. Inflatable pressure, heat and moisture dissipating body supports, such as the one disclosed and illustrated in FIG. 1 of U.S. Pat. No. 5,265,293 to Spahn et al. (“Spahn et al.”) (reproduced as Prior Art in FIG. 4 herein), are now well known in the prior art as being simple, cost effective means to provide hospital patients with effective skin care management.
The inflatable body support illustrated in FIG. 1 of Spahn et al. is formed from a pair of plastic sheets joined together about their common periphery to form a single air pressurizable chamber therebetween. The pair of plastic sheets also have a plurality of aligned holes extending therethrough with the sheets being joined together around the circumference of each hole, thereby preventing air flow from the air pressurizable chamber into the holes, and resulting in a chambered inflatable support with a plurality of holes through and through. Since heat buildup can also lead to tissue breakdown and harbor infection, air circulation is promoted by providing the plurality of holes through and through the air chamber over substantially its entire surface area where a patient's body would actually lie on the inflatable body support. These through holes also permit moisture to flow down and away from a patient, which is a particularly important feature for incontinent patients. The prior art inflatable body supports without holes through and through did not provide adequate heat and moisture dissipation.
The inflatable body support of FIG. 1 of Spahn et al. also has occlusions within the plurality of through holes about the circumference of the inflatable body support where the torso, head and limbs of a patient positioned atop the inflatable body support would not lie. These occlusions totally occlude the through holes, which thereby reduces any distension of the inflatable body support surrounding the occluded holes and effectively volume centers the air within the pressurizable air chamber that is the inflatable body support under where a patient would be laying thereon.
The chambered, air volume centering design of the prior art inflatable body supports of FIG. 1 of Spahn, et al., is designed to provide equal support to the patient's entire body, thereby reducing pressure on any one area to well below the capillary closure pressure to prevent pressure sores and ulcers from developing. Skin friction and deep tissue shear is also minimized through the use of non-abrasive materials of construction, which allows a patient supported thereon to easily move by eliminating friction or resistance. A non-porous, durable, hypo-allergenic vinyl with a flame retardant and an anti-microbial added has been a preferred prior art material to date from which to construct the inflatable body supports of FIG. 1 of Spahn et al.
The air centering, high profile design of the inflatable body supports of FIG. 1 of Spahn, et al., also decreases deep tissue shear in patients because the inflatable body support will contour to the patient's body, thus cradling the body to provide necessary support. This volume centering construction works well for relieving pressures, but it creates a high profile for the inflatable body support, which makes it more difficult for caregivers to reposition or transfer a patient laying on the inflatable body support of FIG. 1 of Spahn et al.
Referring now to Prior Art FIG. 3 of the present application, the inflatable body support of FIG. 1 of Spahn, et al., was modified to provide four (4) oval-shaped hand wells 10 positioned along each of the two longitudinal edges of the inflatable body support, which replaced occluded holes that had been at those locations. These oval-shaped hand wells 10 aided caregivers when transferring a patient laying on the inflatable body support from one substrate surface to another by providing an easy, efficient hand hold, and they further aided caregivers when they needed to “log roll” a patient from side-to-side on the inflatable body support.
The oval-shaped hand wells 10 illustrated in Prior Art FIG. 3 of the present application served well as transfer and repositioning aids. However, referring now to FIGS. 2a and 2b of the present application, when stretching forces were applied to the oval-shaped hand wells 10, the vinyl material defining the oval hand wells 10 stretched, as expected, but the stretched vinyl material also created stress points at the tangent positions of the radiuses of the oval-shaped hand wells, as illustrated in FIG. 2b. This lead to material fatigue at these stress points, and the material fatigue increased the high probability of material failure, including the appearance of pin holes in the material defining the oval-shaped hand wells, with a resulting compromise of the air chamber of the inflatable body support.
Also, the absence of oval-shaped hand wells in the head 11 and foot 12 of the inflatable body support of Prior Art FIG. 3 meant that when a patient was transferred or repositioned thereon, the patient's skeletal system could become torqued out of a desirable alignment when unequal side forces were applied to the oval-shaped hand wells to move the inflatable body support of Prior Art FIG. 3.
Exemplary state of the prior art inflatable body supports illustrated in Prior Art FIG. 3, and described above, are manufactured by EHOB, Inc., in Indianapolis, Ind., and are identified by its WAFFLE® trademark, which is Registered on the Principal Register of the U.S. Trademark Office.